3. Ocular Diagnostic Preparations

Ocular Diagnostic Preparations

This PatientPlus article is written for healthcare professionals so the language may be more technical than the condition leaflets. You may find the abbreviations list helpful.

Topical

  • Use[2] - tear film assessment, identification of corneal epithelial defects/corneal disease and perforation (Seidel test).
  • Action - absorbs light in the blue wavelength and emits green fluorescence.
  • Administration - a single drop is sufficient.
  • Additional information - remember to warn patients that their eye will look yellow but that this readily wears off. They may also find that handkerchiefs stain yellow for several hours after they blow their nose. It stains contact lenses.
Seidel test to detect a wound leak:[3]
  • Apply concentrated fluorescein (eg 2% solution or directly from a moistened fluorescein strip) over the suspect area of the anaesthetised cornea, whilst observing the site with a slit lamp.
  • If there is a leak, the fluorescein dye appears as a bright green fluid oozing from the orange dye concentrate.

Systemic

  • Use - in eye units to perform fundus angiography.
  • Administration - intravenous: it remains largely intravascular and circulates in the blood stream. Patients are monitored for allergic reactions during and after the procedure.
  • Contra-indications - renal impairment and allergy to fluorescein.[4]
  • Side-effects[5] - discolouration of the skin (yellow tinge) and urine, vomiting, itching, sneezing, vasovagal syncope, allergic reactions including anaphylaxis (1 in 1,900: severe, 1 in 220,000: fatal).
  • Use - retinal angiography. Provides a better visualisation of the choroidal (rather than retinal) vasculature. In addition to visualising choroidal neovascularisation, it may also be helpful in assessment of inflammatory disease and choroidal tumours.
  • Administration - intravenous: remains largely intravascular.
  • Contra-indications - pregnancy, renal impairment, iodine allergy.
  • Side-effects - nausea and vomiting, sneezing and pruritus, staining of stool, vasovagal syncope and severe anaphylaxis (1 in 1,900).
  • Use - detection of corneal and conjunctival damage (dessication or devitalised tissue, eg good for diagnosis of keratoconjunctivitis sicca).
  • Action - stains damaged conjunctival and corneal cells.
  • Additional information - this should only be administered after applying topical anaesthetic, as it stings and may cause local irritation on application; advise patients of temporary coloured staining of the eye. The dye needs to be washed out afterwards.
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Further reading & references

  1. Summary of Product Characteristics, fluorets; Fluorescein sodium. Chauvin Pharmaceuticals Ltd: electronic Medicines Compendium. Last updated September 2007.
  2. Jackson TL; Moorfields Manual of Ophthalmology, Mosby (2008)
  3. Kunimoto DY, Kanitkar KD, Makar MS; The Wills Eye Manual, 4th Edition, 2004, Lippincott, Williams and Wilkins. ISBN: 0-7814-4207-2
  4. Denniston AKO, Murray PI. Oxford Handbook of Ophthalmology (OUP), 2009.
  5. Kanski J. Clinical Ophthalmology, A Systematic Approach, 5th Ed, 2003, Butterworth Heinemann
Original Author: Dr Olivia Scott Current Version:
Last Checked: 22/03/2010 Document ID: 375  Version: 2 © EMIS

Disclaimer: This article is for information only and should not be used for the diagnosis or treatment of medical conditions. EMIS has used all reasonable care in compiling the information but make no warranty as to its accuracy. Consult a doctor or other health care professional for diagnosis and treatment of medical conditions. For details see our conditions.